In article , Gary Schafer
writes:

Along the same line consider that the envelope of an SSB signal has no
direct relationship to the original modulation the way that an AM
signal does.

This is why you can not use RF derived ALC to control the audio stage
of an SSB transmitter the way you can with an AM transmitter.

You can't use ENVELOPE detection on SSB the same way it is
done on conventional AM.

But, you CAN use RF-derived feedback - if mixed with a steady
carrier to recover the modulation content - to do that very well.

Or audio clipping that works on AM but does not work the same on SSB.

? Wrongly-done audio clipping on AM is just as bad as on SSB.

RF clipping circuits are quite another thing from audio.

Transmit a square wave on an AM transmitter and you see a square wave
in the AM envelope. Do the same with an SSB transmitter and you only
see sharp spikes in the envelope.

That depends on the frequency of this square wave. That also depends
on what is being used to view the RF envelope. A 50 MHz scope will
show the RF envelope of any HF rig.

Put an electronic keyer on the SSB transmitter and transmit only dots
at a high speed setting. The SSB envelope will show the dots as
dots.

Conversely, if you put a high-purity sinewave audio into a SSB xmtr,
a spectrum analyzer display will show only a single frequency signal.

No one can interchange frequency and time domains directly and
get an explanation. Envelope viewing is time domain. Spectral
analysis is frequency domain.

Len Anderson
retired (from regular hours) electronic engineer person